Electrolytic coating apparatus.



rrtn dramas Patna trrma HEINRICH l/VILHELM BIjTZ,OF.IlUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNOR TO THE FIRM OF COLUMBUSELECTRIZITATSGESELLSCHAFT MIT BESCHRANKTER HAFTUNG, OFLUDIVIGSI'IAFEN-ON-THE-RHINE,

BAVARIA, GERMANY.

ELECTRO'LYTlC COATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 725,208, dated April14, 1903.

Application filed August 6, 1902. Serial No- 118,55Z. (No model.)

T at whom. it may concern.-

Be it known that I, HEINRICH WILHELM BOTZ, engineer, residing atGartenstrasse No. 3 Ludwigshafen-on-the-Rhine,in the Palati- 5 nate,Bavaria, Germany, have invented new and useful Improvements inElectrolytic Coating Apparatus, of which the followingis aspecification.

This invention relates, essentially, to an apparatus forelectrolytically coating sheet metal with zinc in which the zinc anodescan be placed as closely as possible to the metal sheet, suspended orotherwise placed between them, so as to diminish the internal resistance[5 of the bath and save current. The difficulty hitherto experienced inadopting such an arrangement is that the metal sheet to be coated is notof quite even surface, but is frequently bent and undulating, so that itmust be kept in one plane by some means. Unless such means he useddeviations of as much as fifteen centimeters on either side of themedian vertical plane may occur. By the present invention the distancebetween the zinc anodes and the cathode may be reduced to fivecentimeters.

The use of distance-pieces for keeping the anodes and cathode in properrelative positions is open to the objection that the places where thesepieces come in contact with the sheet metal do not get coated, or if theplaces of contact are changed the precipitated zinc thereon has a veryindifferent color.

According to the present invention the dis- 3 5 tance-pieces are made ofa resistant material, like glass or stone ware, and of such form thatthey come in contact with the sheet only at a point or along a line, sothat the surface ofcontact may be reduced to the fraction of a 0millimeterl In the case of a coating of zinc on iron the coating notonly protects the surface actually covered, but the protection extendsto several millimeters from the edge of the coating,

5 so that the portion not covered, owing to the contact of thedistance-pieces made according to this invention, does not tend to rust.Nevertheless, the plates may be shifted during the process, and theinvention also provides for this'movement.

The new distance-pieces are generally of the form of pointed bolts andare fixed in a series on a frame. By moving two such frames, standing orsuspended vertically in the bath,against each other or the one againstthe other all the points are moved to the same extent and bear oppositeeach other on the two surfaces of the metal sheet, which they keepupright and firm between them. This arrangement and movement of thepoints may be effected in one of two ways with respect to thearrangement of the anodes. The latter may be stationaryin thebatl1,while the distance-pieces projecting through holes in the anodesmove to and fro, or the anodes may be moved with the distance-pieces. Asa variation on the latter method only one anode with the correspondingdistance-pieces may be moved, so that the metal sheet is kept againstthe other distance-pieces as a support, and in this case it isadvantageous to suspend the one anode with the distancepieces from acarriage which runs on rails on the upper edge of the electrolytic cell.The stationary anode has at its lower part a horizontal projection inthe direction of the movable anode. On this projection rests the loweredge of the immersed metal sheet whenever the cathode-carriage is movedaway and when the latter is made to approach presses on the stationarycathode.

Another part of this invention consists in suspending plates at thelower edge of the sheet metal as well as at its side edges. In thismanner the high current density at the 8 edges is avoided and thethickening of the deposit thereon is prevented.

When both anodes. are fixed in the bath, the frames carrying thedistance-pieces are attached to a system of levers, so that by ooturning a handle the frames may be made to approach or recede from theanodes, and in order that myinvention may be better understood I haveaffixed drawings, whereof- Figures 1, 2, and 3 are a front View, a plan,and a side View, respectively, of one modifi cation of my invention,whereas Figs. 4, 5, 6 are a front view, a plan, and a side View of apreferred modification.

Referring to Figs. 1 to 3, a is the vat containing the electrolyticalbath, wherein a frame G is placed, consisting of a number of verticalstandards and transverse rods. This frame comprises two equal halves,which are united by cross-bars B and which support the anodes andreceive between themselves the cathode. The two halves of the frame areconnected at their bottom bya plate a, which may be of metal, whereinglass rods (1 are embedded, which support the lower edge of the cathode.The vertical standards are provided with holes f, and the anode-platesare fixed to the frames in any convenient way. 72 represents lightmovable frames carrying the distance-bolts g in series. These bolts aresupported and guided in the holesf and allow horizontal motion of theframes, preserving the vertical position and avancing all the bolts, thepoints thereof being kept in the same vertical plane. Fig. 2 shows thebolts'in their most advanced position, holding between them the cathodesheet metal A.

Fig. 3 shows a mechanism to move the two frames h symmetrically. Thelever K is connected with the rod 70, which swings the crank-levers Z,and thereby moves the rods m and the frames h.

Referring to Figs. 4, 5, and 6, B is a frame fixed to a rod B at itsupper end and supported by a support B at its foot. This frame consistsof the flat iron rails and is provided with one set of distance-bolts gand an anodeplate 0. This frame-is provided with a projection D, whichsupports the cathode-plate A. E is a frame corresponding to and parallelto theframe B and is provided with distance-bolts g and an anode c andsuspended it is desired to introduce the sheet metal to be coated intothe apparatus, the carriage is moved to the right, Fig. 6, the sheet isim mersed, and the carriage moved back until the points of the bolts 9touch the bolts g. The carriage comprises two arms G, on which plates 6are suspended, which shield the side edges of the sheet metal against anexcess of current.

Now what I claim, and desire to secure by Letters Patent, is thefollowing:

1. In an electrolytical apparatus for coating sheet metal, pointeddistance-pieces substantially as described.

2. In an electrolytical apparatus for coating sheet metal, a frameadapted to be moved in vertical position and provided withdistance-pieces, substantially as described.

3. In an electrolytical apparatus for coat ing sheet metal, thecombination of a fixed frame provided with distance-pieces, with amovable frame each provided with distancepieces, and means to remove andcarry back the. movable frame, substantially as described. v

4. In an electrolytical apparatus forcoating sheet metal, thecombination with a frame carrying distance-pieces, with a horizontalprojection at the foot thereof, substantially as described.

5. In an electrolytical apparatus for coating sheet metal, thecombination with two frames carrying the anodes, of shieldingplatesprovided at the sides of the anodes, substantially as described.

6. In an electrolytical apparatus for coating sheet metal, thecombination with a fixed anode, of a horizontal support at the footthereof, a movable anode guided in vertical position, and a carriagesupporting the said movable anode, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of

